#!/usr/bin/env python3
import sys, os, struct

def parse_appledouble(ad_path):
    """
    Open an AppleDouble file and return (file_type, creator_code).
    """

    # Auxiliary function to decode 8 bytes → (ft, cr)
    def decode_codes(data):
        ft_bytes, cr_bytes = data[:4], data[4:8]
        # decode ASCII, trim NULs
        ft = ft_bytes.decode("ascii", errors="ignore").replace("\x00", "")
        cr = cr_bytes.decode("ascii", errors="ignore").replace("\x00", "")
        # validate 4 alphanumeric characters
        if len(ft) == 4 and ft.isalnum() and len(cr) == 4 and cr.isalnum():
            return ft, cr
        return "", ""

    with open(ad_path, "rb") as f:
        # skip to number of entries (big‑endian uint16 at offset 24)
        f.seek(24)
        num_entries, = struct.unpack(">H", f.read(2))

        # find offsets and lengths for entries 9 and 2
        off9 = len9 = off2 = len2 = None
        f.seek(26)
        for _ in range(num_entries):
            entry_id, entry_off, entry_len = struct.unpack(">III", f.read(12))
            if entry_id == 9:
                off9, len9 = entry_off, entry_len
            elif entry_id == 2:
                off2, len2 = entry_off, entry_len

        # 1) Try Finder Info (entry 9)
        if off9 is not None and len9 >= 8:
            f.seek(off9)
            data = f.read(8)
            ft, cr = decode_codes(data)
            if ft and cr:
                return ft, cr

        # 2) Fallback to Resource Fork (entry 2)
        if off2 is not None and len2 >= 16:
            # read mapOffset (big‑endian uint32 at off2+4)
            f.seek(off2 + 4)
            map_off, = struct.unpack(">I", f.read(4))
            # embedded Finder Info is at off2 + mapOffset + 16
            f.seek(off2 + map_off + 16)
            data = f.read(8)
            ft, cr = decode_codes(data)
            if ft and cr:
                return ft, cr

        # if all else fails, return empty strings
        return "", ""

def main():
    if len(sys.argv) < 2:
        print("Usage: get_type_creator.py <datafile> [<datafile>...]", file=sys.stderr)
        sys.exit(1)

    for datafile in sys.argv[1:]:
        dirpath, base = os.path.split(datafile)
        apple = os.path.join(dirpath, "@eaDir", f"{base}@SynoResource")
        if not os.path.isfile(apple):
            # print empty fields if no AppleDouble
            # print(f"{datafile}\t\t")
            continue

        ft, cr = parse_appledouble(apple)
        # only print if both codes are non‐empty
        if ft and cr:
            print(f"{datafile}\t{ft}\t{cr}")

if __name__ == "__main__":
    main()